A 94 GHz Array Antenna for 45° Linear Polarization in LTCC Technology

This paper proposed a 94 GHz planar array antenna for 45° linear polarization (LP) in low temperature co-fired ceramic technology (LTCC). First, the antenna is aperture-fed through a slot cut on the substrate integrated waveguide (SIW). Then the array is fed by the 1-to-4 microstrip divider to form 2 × 2 radiation units. Two prototype array antennas with rectangular and circular elements at 94 GHz are designed and fabricated, respectively. The prototype with rectangular elements achieves a 5.6% bandwidth (|S
₁₁
| <; -10 dB) from 90.8 GHz to 96 GHz with a gain varied from 7.2 dBi to 8.8 dBi while the prototype with circular elements achieves a 4.5% bandwidth from 91.2 GHz to 95.4 GHz with a gain varied from 7.2 dBi to 9.4 dBi.